<%
private const bits_to_a_byte = 8
private const bytes_to_a_word = 4
private const bits_to_a_word = 32

private m_lonbits(30)
private m_l2power(30)
 
private function lshift(lvalue, ishiftbits)
    if ishiftbits = 0 then
        lshift = lvalue
        exit function
    elseif ishiftbits = 31 then
        if lvalue and 1 then
            lshift = &h80000000
        else
            lshift = 0
        end if
        exit function
    elseif ishiftbits < 0 or ishiftbits > 31 then
        err.raise 6
    end if

    if (lvalue and m_l2power(31 - ishiftbits)) then
        lshift = ((lvalue and m_lonbits(31 - (ishiftbits + 1))) * m_l2power(ishiftbits)) or &h80000000
    else
        lshift = ((lvalue and m_lonbits(31 - ishiftbits)) * m_l2power(ishiftbits))
    end if
end function

private function rshift(lvalue, ishiftbits)
    if ishiftbits = 0 then
        rshift = lvalue
        exit function
    elseif ishiftbits = 31 then
        if lvalue and &h80000000 then
            rshift = 1
        else
            rshift = 0
        end if
        exit function
    elseif ishiftbits < 0 or ishiftbits > 31 then
        err.raise 6
    end if
    
    rshift = (lvalue and &h7ffffffe) \ m_l2power(ishiftbits)

    if (lvalue and &h80000000) then
        rshift = (rshift or (&h40000000 \ m_l2power(ishiftbits - 1)))
    end if
end function

private function rotateleft(lvalue, ishiftbits)
    rotateleft = lshift(lvalue, ishiftbits) or rshift(lvalue, (32 - ishiftbits))
end function

private function addunsigned(lx, ly)
    dim lx4
    dim ly4
    dim lx8
    dim ly8
    dim lresult
 
    lx8 = lx and &h80000000
    ly8 = ly and &h80000000
    lx4 = lx and &h40000000
    ly4 = ly and &h40000000
 
    lresult = (lx and &h3fffffff) + (ly and &h3fffffff)
 
    if lx4 and ly4 then
        lresult = lresult xor &h80000000 xor lx8 xor ly8
    elseif lx4 or ly4 then
        if lresult and &h40000000 then
            lresult = lresult xor &hc0000000 xor lx8 xor ly8
        else
            lresult = lresult xor &h40000000 xor lx8 xor ly8
        end if
    else
        lresult = lresult xor lx8 xor ly8
    end if
 
    addunsigned = lresult
end function

private function md5_f(x, y, z)
    md5_f = (x and y) or ((not x) and z)
end function

private function md5_g(x, y, z)
    md5_g = (x and z) or (y and (not z))
end function

private function md5_h(x, y, z)
    md5_h = (x xor y xor z)
end function

private function md5_i(x, y, z)
    md5_i = (y xor (x or (not z)))
end function

private sub md5_ff(a, b, c, d, x, s, ac)
    a = addunsigned(a, addunsigned(addunsigned(md5_f(b, c, d), x), ac))
    a = rotateleft(a, s)
    a = addunsigned(a, b)
end sub

private sub md5_gg(a, b, c, d, x, s, ac)
    a = addunsigned(a, addunsigned(addunsigned(md5_g(b, c, d), x), ac))
    a = rotateleft(a, s)
    a = addunsigned(a, b)
end sub

private sub md5_hh(a, b, c, d, x, s, ac)
    a = addunsigned(a, addunsigned(addunsigned(md5_h(b, c, d), x), ac))
    a = rotateleft(a, s)
    a = addunsigned(a, b)
end sub

private sub md5_ii(a, b, c, d, x, s, ac)
    a = addunsigned(a, addunsigned(addunsigned(md5_i(b, c, d), x), ac))
    a = rotateleft(a, s)
    a = addunsigned(a, b)
end sub

private function converttowordarray(smessage)
    dim lmessagelength
    dim lnumberofwords
    dim lwordarray()
    dim lbyteposition
    dim lbytecount
    dim lwordcount
    
    const modulus_bits = 512
    const congruent_bits = 448
    
    lmessagelength = len(smessage)
    
    lnumberofwords = (((lmessagelength + ((modulus_bits - congruent_bits) \ bits_to_a_byte)) \ (modulus_bits \ bits_to_a_byte)) + 1) * (modulus_bits \ bits_to_a_word)
    redim lwordarray(lnumberofwords - 1)
    
    lbyteposition = 0
    lbytecount = 0
    do until lbytecount >= lmessagelength
        lwordcount = lbytecount \ bytes_to_a_word
        lbyteposition = (lbytecount mod bytes_to_a_word) * bits_to_a_byte
        lwordarray(lwordcount) = lwordarray(lwordcount) or lshift(asc(mid(smessage, lbytecount + 1, 1)), lbyteposition)
        lbytecount = lbytecount + 1
    loop

    lwordcount = lbytecount \ bytes_to_a_word
    lbyteposition = (lbytecount mod bytes_to_a_word) * bits_to_a_byte

    lwordarray(lwordcount) = lwordarray(lwordcount) or lshift(&h80, lbyteposition)

    lwordarray(lnumberofwords - 2) = lshift(lmessagelength, 3)
    lwordarray(lnumberofwords - 1) = rshift(lmessagelength, 29)
    
    converttowordarray = lwordarray
end function

private function wordtohex(lvalue)
    dim lbyte
    dim lcount
    
    for lcount = 0 to 3
        lbyte = rshift(lvalue, lcount * bits_to_a_byte) and m_lonbits(bits_to_a_byte - 1)
        wordtohex = wordtohex & right("0" & hex(lbyte), 2)
    next
end function

public function md5(smessage)
    m_lonbits(0) = clng(1)
    m_lonbits(1) = clng(3)
    m_lonbits(2) = clng(7)
    m_lonbits(3) = clng(15)
    m_lonbits(4) = clng(31)
    m_lonbits(5) = clng(63)
    m_lonbits(6) = clng(127)
    m_lonbits(7) = clng(255)
    m_lonbits(8) = clng(511)
    m_lonbits(9) = clng(1023)
    m_lonbits(10) = clng(2047)
    m_lonbits(11) = clng(4095)
    m_lonbits(12) = clng(8191)
    m_lonbits(13) = clng(16383)
    m_lonbits(14) = clng(32767)
    m_lonbits(15) = clng(65535)
    m_lonbits(16) = clng(131071)
    m_lonbits(17) = clng(262143)
    m_lonbits(18) = clng(524287)
    m_lonbits(19) = clng(1048575)
    m_lonbits(20) = clng(2097151)
    m_lonbits(21) = clng(4194303)
    m_lonbits(22) = clng(8388607)
    m_lonbits(23) = clng(16777215)
    m_lonbits(24) = clng(33554431)
    m_lonbits(25) = clng(67108863)
    m_lonbits(26) = clng(134217727)
    m_lonbits(27) = clng(268435455)
    m_lonbits(28) = clng(536870911)
    m_lonbits(29) = clng(1073741823)
    m_lonbits(30) = clng(2147483647)
    
    m_l2power(0) = clng(1)
    m_l2power(1) = clng(2)
    m_l2power(2) = clng(4)
    m_l2power(3) = clng(8)
    m_l2power(4) = clng(16)
    m_l2power(5) = clng(32)
    m_l2power(6) = clng(64)
    m_l2power(7) = clng(128)
    m_l2power(8) = clng(256)
    m_l2power(9) = clng(512)
    m_l2power(10) = clng(1024)
    m_l2power(11) = clng(2048)
    m_l2power(12) = clng(4096)
    m_l2power(13) = clng(8192)
    m_l2power(14) = clng(16384)
    m_l2power(15) = clng(32768)
    m_l2power(16) = clng(65536)
    m_l2power(17) = clng(131072)
    m_l2power(18) = clng(262144)
    m_l2power(19) = clng(524288)
    m_l2power(20) = clng(1048576)
    m_l2power(21) = clng(2097152)
    m_l2power(22) = clng(4194304)
    m_l2power(23) = clng(8388608)
    m_l2power(24) = clng(16777216)
    m_l2power(25) = clng(33554432)
    m_l2power(26) = clng(67108864)
    m_l2power(27) = clng(134217728)
    m_l2power(28) = clng(268435456)
    m_l2power(29) = clng(536870912)
    m_l2power(30) = clng(1073741824)


    dim x
    dim k
    dim aa
    dim bb
    dim cc
    dim dd
    dim a
    dim b
    dim c
    dim d
    
    const s11 = 7
    const s12 = 12
    const s13 = 17
    const s14 = 22
    const s21 = 5
    const s22 = 9
    const s23 = 14
    const s24 = 20
    const s31 = 4
    const s32 = 11
    const s33 = 16
    const s34 = 23
    const s41 = 6
    const s42 = 10
    const s43 = 15
    const s44 = 21

    x = converttowordarray(smessage)
    
    a = &h67452301
    b = &hefcdab89
    c = &h98badcfe
    d = &h10325476

    for k = 0 to ubound(x) step 16
        aa = a
        bb = b
        cc = c
        dd = d
    
        md5_ff a, b, c, d, x(k + 0), s11, &hd76aa478
        md5_ff d, a, b, c, x(k + 1), s12, &he8c7b756
        md5_ff c, d, a, b, x(k + 2), s13, &h242070db
        md5_ff b, c, d, a, x(k + 3), s14, &hc1bdceee
        md5_ff a, b, c, d, x(k + 4), s11, &hf57c0faf
        md5_ff d, a, b, c, x(k + 5), s12, &h4787c62a
        md5_ff c, d, a, b, x(k + 6), s13, &ha8304613
        md5_ff b, c, d, a, x(k + 7), s14, &hfd469501
        md5_ff a, b, c, d, x(k + 8), s11, &h698098d8
        md5_ff d, a, b, c, x(k + 9), s12, &h8b44f7af
        md5_ff c, d, a, b, x(k + 10), s13, &hffff5bb1
        md5_ff b, c, d, a, x(k + 11), s14, &h895cd7be
        md5_ff a, b, c, d, x(k + 12), s11, &h6b901122
        md5_ff d, a, b, c, x(k + 13), s12, &hfd987193
        md5_ff c, d, a, b, x(k + 14), s13, &ha679438e
        md5_ff b, c, d, a, x(k + 15), s14, &h49b40821
    
        md5_gg a, b, c, d, x(k + 1), s21, &hf61e2562
        md5_gg d, a, b, c, x(k + 6), s22, &hc040b340
        md5_gg c, d, a, b, x(k + 11), s23, &h265e5a51
        md5_gg b, c, d, a, x(k + 0), s24, &he9b6c7aa
        md5_gg a, b, c, d, x(k + 5), s21, &hd62f105d
        md5_gg d, a, b, c, x(k + 10), s22, &h2441453
        md5_gg c, d, a, b, x(k + 15), s23, &hd8a1e681
        md5_gg b, c, d, a, x(k + 4), s24, &he7d3fbc8
        md5_gg a, b, c, d, x(k + 9), s21, &h21e1cde6
        md5_gg d, a, b, c, x(k + 14), s22, &hc33707d6
        md5_gg c, d, a, b, x(k + 3), s23, &hf4d50d87
        md5_gg b, c, d, a, x(k + 8), s24, &h455a14ed
        md5_gg a, b, c, d, x(k + 13), s21, &ha9e3e905
        md5_gg d, a, b, c, x(k + 2), s22, &hfcefa3f8
        md5_gg c, d, a, b, x(k + 7), s23, &h676f02d9
        md5_gg b, c, d, a, x(k + 12), s24, &h8d2a4c8a
            
        md5_hh a, b, c, d, x(k + 5), s31, &hfffa3942
        md5_hh d, a, b, c, x(k + 8), s32, &h8771f681
        md5_hh c, d, a, b, x(k + 11), s33, &h6d9d6122
        md5_hh b, c, d, a, x(k + 14), s34, &hfde5380c
        md5_hh a, b, c, d, x(k + 1), s31, &ha4beea44
        md5_hh d, a, b, c, x(k + 4), s32, &h4bdecfa9
        md5_hh c, d, a, b, x(k + 7), s33, &hf6bb4b60
        md5_hh b, c, d, a, x(k + 10), s34, &hbebfbc70
        md5_hh a, b, c, d, x(k + 13), s31, &h289b7ec6
        md5_hh d, a, b, c, x(k + 0), s32, &heaa127fa
        md5_hh c, d, a, b, x(k + 3), s33, &hd4ef3085
        md5_hh b, c, d, a, x(k + 6), s34, &h4881d05
        md5_hh a, b, c, d, x(k + 9), s31, &hd9d4d039
        md5_hh d, a, b, c, x(k + 12), s32, &he6db99e5
        md5_hh c, d, a, b, x(k + 15), s33, &h1fa27cf8
        md5_hh b, c, d, a, x(k + 2), s34, &hc4ac5665
    
        md5_ii a, b, c, d, x(k + 0), s41, &hf4292244
        md5_ii d, a, b, c, x(k + 7), s42, &h432aff97
        md5_ii c, d, a, b, x(k + 14), s43, &hab9423a7
        md5_ii b, c, d, a, x(k + 5), s44, &hfc93a039
        md5_ii a, b, c, d, x(k + 12), s41, &h655b59c3
        md5_ii d, a, b, c, x(k + 3), s42, &h8f0ccc92
        md5_ii c, d, a, b, x(k + 10), s43, &hffeff47d
        md5_ii b, c, d, a, x(k + 1), s44, &h85845dd1
        md5_ii a, b, c, d, x(k + 8), s41, &h6fa87e4f
        md5_ii d, a, b, c, x(k + 15), s42, &hfe2ce6e0
        md5_ii c, d, a, b, x(k + 6), s43, &ha3014314
        md5_ii b, c, d, a, x(k + 13), s44, &h4e0811a1
        md5_ii a, b, c, d, x(k + 4), s41, &hf7537e82
        md5_ii d, a, b, c, x(k + 11), s42, &hbd3af235
        md5_ii c, d, a, b, x(k + 2), s43, &h2ad7d2bb
        md5_ii b, c, d, a, x(k + 9), s44, &heb86d391
    
        a = addunsigned(a, aa)
        b = addunsigned(b, bb)
        c = addunsigned(c, cc)
        d = addunsigned(d, dd)
    next
    
    'md5 = lcase(wordtohex(a) & wordtohex(b) & wordtohex(c) & wordtohex(d))
    md5=lcase(wordtohex(b) & wordtohex(c))  'i crop this to fit 16byte database password :d
end function
%>

